Linux » Linux Kernel : Security Vulnerabilities, CVEs, Published In 2021

A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space

The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix alu32 const subreg bound tracking on bitwise operations") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 ("bpf:Fix a verifier failure with xor") ( 5.10-rc1).

In the IPv4 implementation in the Linux kernel before 5.12.4, net/ipv4/route.c has an information leak because the hash table is very small.

In the IPv6 implementation in the Linux kernel before 5.13.3, net/ipv6/output_core.c has an information leak because of certain use of a hash table which, although big, doesn't properly consider that IPv6-based attackers can typically choose among many IPv6 source addresses.

An issue was discovered in the Linux kernel before 5.15.11. There is a memory leak in the __rds_conn_create() function in net/rds/connection.c in a certain combination of circumstances.

In __f2fs_setxattr in fs/f2fs/xattr.c in the Linux kernel through 5.15.11, there is an out-of-bounds memory access when an inode has an invalid last xattr entry.

pep_sock_accept in net/phonet/pep.c in the Linux kernel through 5.15.8 has a refcount leak.

A use-after-free exists in drivers/tee/tee_shm.c in the TEE subsystem in the Linux kernel through 5.15.11. This occurs because of a race condition in tee_shm_get_from_id during an attempt to free a shared memory object.

In the Linux kernel through 5.15.2, mwifiex_usb_recv in drivers/net/wireless/marvell/mwifiex/usb.c allows an attacker (who can connect a crafted USB device) to cause a denial of service (skb_over_panic).

In the Linux kernel through 5.15.2, hw_atl_utils_fw_rpc_wait in drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils.c allows an attacker (who can introduce a crafted device) to trigger an out-of-bounds write via a crafted length value.

An issue was discovered in the Linux kernel before 5.14.15. There is an array-index-out-of-bounds flaw in the detach_capi_ctr function in drivers/isdn/capi/kcapi.c.

An issue was discovered in net/tipc/crypto.c in the Linux kernel before 5.14.16. The Transparent Inter-Process Communication (TIPC) functionality allows remote attackers to exploit insufficient validation of user-supplied sizes for the MSG_CRYPTO message type.

An issue was discovered in the Linux kernel before 5.14.8. A use-after-free in selinux_ptrace_traceme (aka the SELinux handler for PTRACE_TRACEME) could be used by local attackers to cause memory corruption and escalate privileges, aka CID-a3727a8bac0a. This occurs because of an attempt to access the subjective credentials of another task.

An issue was discovered in the Linux kernel for powerpc before 5.14.15. It allows a malicious KVM guest to crash the host, when the host is running on Power8, due to an arch/powerpc/kvm/book3s_hv_rmhandlers.S implementation bug in the handling of the SRR1 register values.

The firewire subsystem in the Linux kernel through 5.14.13 has a buffer overflow related to drivers/media/firewire/firedtv-avc.c and drivers/media/firewire/firedtv-ci.c, because avc_ca_pmt mishandles bounds checking.

dp_link_settings_write in drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c in the Linux kernel through 5.14.14 allows a heap-based buffer overflow by an attacker who can write a string to the AMD GPU display drivers debug filesystem. There are no checks on size within parse_write_buffer_into_params when it uses the size of copy_from_user to copy a userspace buffer into a 40-byte heap buffer.

An issue was discovered in aspeed_lpc_ctrl_mmap in drivers/soc/aspeed/aspeed-lpc-ctrl.c in the Linux kernel before 5.14.6. Local attackers able to access the Aspeed LPC control interface could overwrite memory in the kernel and potentially execute privileges, aka CID-b49a0e69a7b1. This occurs because a certain comparison uses values that are not memory sizes.

The decode_data function in drivers/net/hamradio/6pack.c in the Linux kernel before 5.13.13 has a slab out-of-bounds write. Input from a process that has the CAP_NET_ADMIN capability can lead to root access.

prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the Linux kernel before 5.14.12 allows unprivileged users to trigger an eBPF multiplication integer overflow with a resultant out-of-bounds write.

loop_rw_iter in fs/io_uring.c in the Linux kernel 5.10 through 5.14.6 allows local users to gain privileges by using IORING_OP_PROVIDE_BUFFERS to trigger a free of a kernel buffer, as demonstrated by using /proc/<pid>/maps for exploitation.

A race condition was discovered in ext4_write_inline_data_end in fs/ext4/inline.c in the ext4 subsystem in the Linux kernel through 5.13.13.

arch/mips/net/bpf_jit.c in the Linux kernel before 5.4.10 can generate undesirable machine code when transforming unprivileged cBPF programs, allowing execution of arbitrary code within the kernel context. This occurs because conditional branches can exceed the 128 KB limit of the MIPS architecture.

net/netfilter/nf_conntrack_standalone.c in the Linux kernel before 5.12.2 allows observation of changes in any net namespace because these changes are leaked into all other net namespaces. This is related to the NF_SYSCTL_CT_MAX, NF_SYSCTL_CT_EXPECT_MAX, and NF_SYSCTL_CT_BUCKETS sysctls.

net/nfc/llcp_sock.c in the Linux kernel before 5.12.10 allows local unprivileged users to cause a denial of service (NULL pointer dereference and BUG) by making a getsockname call after a certain type of failure of a bind call.

drivers/net/ethernet/xilinx/ll_temac_main.c in the Linux kernel before 5.12.13 allows remote attackers to cause a denial of service (buffer overflow and lockup) by sending heavy network traffic for about ten minutes.